The following abbreviations are herewith defined, at least some of which are referred to in the following description associated with the prior art and the present invention.    ATM Asynchronous Transfer Mode    BRAS Broadband Remote Access Server    BTV Broadcast Television    CC Connectivity Check    DA Destination Address    DSL Digital Subscriber Line    DSLAM Digital Subscriber Line Access Multiplexer    IEEE Institute of Electrical and Electronics Engineers    IP Internet Protocol    IPTV Internet Protocol Television    LB Loopback    LBR Loopback Reply    LT Line Termination (customer-side of a DSLAM)    NT Network Termination (network-side of a DSLAM)    MAC Media Access Control    MEP Maintenance End Point    OAM Operation, Administration and Maintenance    OLT Optical Line Termination    ONT Optical Network Termination    PON Passive Optical Network    RGW Residential Gateway    SA Source Address    TV Television    VCI Virtual Connection Identifier    VPI Virtual Pipe Identifier
Referring to FIGS. 1-2 (PRIOR ART), there are two block diagrams of a traditional access network 100 with Ethernet-based DSL aggregation (e.g., see DSL Forum TR-101). The traditional access network 100 (e.g., IPTV network 100) includes a regional network 102 which is coupled to an edge router 104 (e.g., BRAS 104 with ports 105) which is coupled to one or more aggregation nodes 106 (with ports 106a and 106b). The aggregation node(s) 106 are connected by an Ethernet access network 108 to multiple access nodes 110 (e.g., DSLAMs 110 each of which include a NT card 113 which has NT exterior-facing ports 113a and NT interior-facing ports 113b and a LT card 115 which has LT interior-facing ports 115a and LT exterior facing ports 115b). The DSLAMs 110 are connected to multiple CPEs 112 (RGWs 112) which in turn are associated with multiple customers 114 where there is normally one customer 114 associated with one CPE 112. In one application, the BRAS 104 transmits BTV traffic 118 (multiple TV channels 118) at the Ethernet level (level 2) downstream via the aggregation node(s) 106, the Ethernet access network 108, the DSLAMs 110, and the CPEs 112 to the customers 114. The basic architecture and functionality of the traditional access network 100 is well known to those skilled in the art but for additional details about this type of architecture reference is made to DSL Forum TR-101 Ethernet-based DSL aggregation dated April 2006 (the contents of which are hereby incorporated by reference herein).
The traditional access network 100 typically implements a connectivity fault management scheme (EthCFM or EthOAM) that has been disclosed in the IEEE 802.1 ag/D8 standard entitled “Virtual Bridged Local Area Networks-Amendment 5: Connectivity Fault Management” Feb. 8, 2007 (the contents of which are incorporated by reference herein). In one application, the BRAS 104 may use this standard to send an Ethernet OAM loopback message to test the connectivity of a particular CPE 112′. However, before the BRAS 104 can send the loopback message to test the connectivity of a particular CPE 112′ it needs to know the MAC address of the particular CPE 112′. Unfortunately, the standard assumes that the BRAS 104 would apriori know the MAC addresses of all of the CPEs 112. In the past, the operator enabled the BRAS 104 to learn the MAC address of the CPEs 112 by ensuring a MEP 116 is pre-configured (with a unique MEP-id) in each of the CPEs 112. Then, the operator pre-configured the BRAS 104 to have knowledge about the MEPs 116 in each of the CPEs 112. Thereafter, the BRAS 104 used in-band 802.1ag CC messages containing information about the CPE's MEPs 116 to learn the corresponding MAC addresses of the CPEs 112. This approach has two problems: 1) it is not scalable in an access network 100 that has many thousands of CPEs 112 (i.e., the BRAS 104 can not send just one CC message to learn the MAC address of one particular CPE 112′); and 2) there is a security issue because a hacker could generate CC messages with a false MEP-id and as such the BRAS 104 would obtain and then link the wrong MAC address to the CPE's MEP. Accordingly, there has been a need and still is a need for addressing this shortcoming and other shortcomings that are associated with the traditional access network 100. This need and other needs are satisfied by the present invention.